"Our international performance came in at $29.2 million, largely attributable to project timing of a large customer in Latin America," he said. "As we have said several times over the last year, the markets we serve in general experienced a significant pullback in spending, which affected us in several areas. By far, the largest impact occurred in our products, both enterprise and carrier, which are sold to carriers."

James Matthews, Adtran's chief financial officer, said during the call that he expects first-quarter 2013 revenues to be in the range of fourth-quarter 2012, but that operating expenses should be flat or slightly down.

"We believe the larger factors impacting the total revenue we realized for the first quarter of 2013 will be the following: The macro spending environment for carriers and enterprise; regulatory uncertainty in the domestic carrier market; professional services activity levels, both domestic and international; the timing of revenue related to Broadband Stimulus projects; and the adoption rate of our Broadband Access platforms," he said.